Vacuum port having a flow disruptor

ABSTRACT

An intake system is provided. The intake system including an intake manifold coupled to an engine and a vacuum port located in said intake manifold and in an air flow path downstream of a throttle body, the vacuum port including a molded flow disruptor including a cross-beam traversing an outlet of the vacuum port. The intake system may further include a vacuum passage coupling the vacuum port to a vehicle subsystem.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/823,926 filed Jun. 25, 2010, the entire contents of whichare hereby incorporated by reference for all purposes.

BACKGROUND/SUMMARY

Intake manifolds in internal combustion engines may include variousports for introducing gases into the intake manifold. In some examples,the ports may be coupled to systems which utilize the vacuum generatedwithin the intake manifold to supplement various operations. Forexample, the intake manifold may be in fluidic communication with apositive crankcase ventilation system, a brake system, an evaporativeemission system (e.g., vapor canisters), etc. However, objectionablenoises, such as whistling, may be generated within the ports and theintake manifold during engine operation due to the flow characteristicswithin the aforementioned components. Furthermore, in some systems gasesintroduced into the intake manifold from the ports may not fully mixwith the air in the intake manifold, increasing combustion variabilityand decreasing engine efficiency.

Some intake systems have used ramps positioned upstream of the ports inthe intake manifold to reduce unwanted noise, as well as to promotemixing. However, the inventors herein have recognized variousshortcomings with such an above approach. For example, ramps mayincrease losses within the intake manifold, thereby decreasing pressurewithin the intake manifold. Decreased intake manifold pressure may inturn degrade engine operation during certain operating conditions, suchas when the throttle is fully open. Furthermore, it may be unfeasible toincorporate a ramp into an intake manifold using certain constructiontechniques, such as shell molding. Therefore, to incorporate ramps intoan intake manifold, retrofitting of the intake manifold may be requiredor alternatively more complex and expensive construction techniques maybe needed, increasing production costs.

As such, various example systems and approaches are described herein. Inone example an intake system is provided. The intake system may includean intake manifold coupled to an engine and a vacuum port located insaid intake manifold and in an air flow path downstream of a throttlebody and upstream of a plurality of intake runners. The vacuum port mayinclude a molded flow disruptor including a cross-beam traversing anoutlet of the vacuum port. The intake system may further include avacuum passage coupling the vacuum port to a vehicle subsystem.

In this way, it is possible to reduce unwanted noises while promotingmixing of the gases from the port with the intake air. In particular thecross-beam splits the flows of the gases through the vacuum portgenerating a turbulent wake downstream of the cross-beam in the intakemanifold, thereby promoting mixing of the gas from the vacuum port withgas from the throttle body. Furthermore, in some embodiments the intakemanifold and flow disruptor may be integrally molded using shellmolding. In this way, the intake manifold and vacuum port may bemanufactured utilizing a low cost technique.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Furthermore,the claimed subject matter is not limited to implementations that solveany or all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a schematic depiction of an internal combustion engine.

FIG. 2 shows a schematic depiction of a vehicle including the internalcombustion engine shown in FIG. 1.

FIG. 3 shows a perspective view of an example intake manifold drawnapproximately to scale.

FIG. 4 shows a cross-sectional view of a lower shell of the intakemanifold shown in FIG. 3 drawn approximately to scale.

FIG. 5 shows another cross-sectional view of the lower shell of theintake manifold shown in FIG. 3 drawn approximately to scale.

FIG. 6 shows a cross-sectional view of the intake runners included inthe intake manifold shown in FIG. 3 drawn approximately to scale.

FIG. 7 shows a bottom view of the intake manifold shown in FIG. 3 drawnapproximately to scale.

FIG. 8 shows a front view of the intake manifold shown in FIG. 3 drawnapproximately to scale.

FIG. 9 shows a side view of the intake manifold shown in FIG. 3 drawnapproximately to scale.

FIG. 10 shows a method for operation of an intake system in an internalcombustion engine.

DETAILED DESCRIPTION

An intake manifold having a vacuum port including a flow disruptor isdisclosed herein. The vacuum port may be positioned downstream of athrottle body and upstream of a plurality of intake runners. The flowdisruptor may increase turbulence within the intake manifold. In turnthe turbulence may promote mixing of the gases from the vacuum port withgases from a throttle body positioned upstream of the intake manifold.Additionally, the turbulence generated via the flow disruptor maydecrease flow-generated noises within the intake manifold. In this way,both customer satisfaction and combustion efficiency may be increased.

FIGS. 1 and 2 show schematic depictions of an engine and accompanyingintake system. FIG. 3 shows a perspective view of an example intakemanifold including a vacuum port having a flow disruptor. FIGS. 4 and 5show various views of a lower shell of the intake manifold shown in FIG.3. FIG. 6 shows a cross-sectional view of intake runners positioneddownstream of the flow disruptor in the intake manifold shown in FIG. 3.FIGS. 7-9 show additional views of the intake manifold shown in FIG. 3and FIG. 10 shows a method for operation of an intake system.

Referring to FIG. 1, internal combustion engine 10, comprising aplurality of cylinders, one cylinder of which is shown in FIG. 1, iscontrolled by electronic engine controller 12. Engine 10 includescombustion chamber 30 and cylinder walls 32 with piston 36 positionedtherein and connected to crankshaft 40. Combustion chamber 30 is showncommunicating with intake manifold 44 and exhaust manifold 48 viarespective intake valve 52 and exhaust valve 54. Each intake and exhaustvalve may be operated by an intake cam 51 and an exhaust cam 53.Alternatively, one or more of the intake and exhaust valves may beoperated by an electromechanically controlled valve coil and armatureassembly. The position of intake cam 51 may be determined by intake camsensor 55. The position of exhaust cam 53 may be determined by exhaustcam sensor 57.

Intake manifold 44 is also shown intermediate of intake valve 52 and airintake zip tube 42. Fuel is delivered to fuel injector 66 by a fuelsystem (not shown) including a fuel tank, fuel pump, and fuel rail.Engine 10 of FIG. 1 is configured such that the fuel is injecteddirectly into the engine cylinder, which is known to those skilled inthe art as direct injection. However, port injection may be used inother embodiments. Fuel injector 66 is supplied operating current fromdriver 68 which responds to controller 12. In addition, intake manifold44 is shown communicating with optional electronic throttle 62 withthrottle plate 64. In one example, a low pressure direct injectionsystem may be used, where fuel pressure can be raised to approximately20-30 bar. Alternatively, a high pressure, dual stage, fuel system maybe used to generate higher fuel pressures.

A first vacuum port 80 and a second vacuum port 82 are coupled to intakemanifold 44. The first vacuum port is coupled to vacuum passage 84 andthe second vacuum port is coupled to vacuum passage 86. Each vacuumpassage may be coupled to one of the following vehicle subsystems 99: abrake system, a crankcase ventilation system, an evaporative emissionsystem, and an exhaust gas recirculation (EGR) system. Therefore, thefirst vacuum port may be a brake boost port, a positive crankcaseventilation port, or a fuel vapor purge port. In this way gases from theaforementioned subsystems may be drawn into the intake manifold duringcertain engine operating conditions, such as when the intake manifold isbelow atmospheric pressure. As shown, the first vacuum port includes aflow disruptor 88, and the second vacuum port does not include a flowdisruptor. Although the flow disruptor is generically represented as abox it will be appreciated that the flow disruptor may have a geometricconfiguration conducive to reducing flow-generated noise within theintake manifold. FIGS. 3-5 show detailed illustrations of an exampleflow disruptor, discussed in greater detail herein. Further in otherembodiments additional vacuum ports may be coupled to the intakemanifold. Furthermore, the second vacuum port and/or the additionalvacuum ports may also include flow disruptors.

Distributorless ignition system 90 provides an ignition spark tocombustion chamber 30 via spark plug 92 in response to controller 12.Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown coupled toexhaust manifold 48 upstream of catalytic converter 70. Alternatively, atwo-state exhaust gas oxygen sensor may be substituted for UEGO sensor126.

Converter 70 can include multiple catalyst bricks, in one example. Inanother example, multiple emission control devices, each with multiplebricks, can be used. Converter 70 can be a three-way type catalyst inone example.

Controller 12 is shown in FIG. 1 as a microcomputer including:microprocessor unit 102, input/output ports 104, read-only memory 106,random access memory 108, keep alive memory 110, and a data bus.Controller 12 is shown receiving various signals from sensors coupled toengine 10, in addition to those signals previously discussed, including:engine coolant temperature (ECT) from temperature sensor 112 coupled tocooling sleeve 114; a position sensor 134 coupled to an acceleratorpedal 130 for sensing force applied by foot 132; a measurement of enginemanifold pressure (MAP) from pressure sensor 122 coupled to intakemanifold 44; an engine position sensor from a Hall effect sensor 118sensing crankshaft 40 position; a measurement of air mass entering theengine from sensor 120; and a measurement of throttle position fromsensor 58. Barometric pressure may also be sensed (sensor not shown) forprocessing by controller 12. In a preferred aspect of the presentdescription, engine position sensor 118 produces a predetermined numberof equally spaced pulses every revolution of the crankshaft from whichengine speed (RPM) can be determined.

During operation, each cylinder within engine 10 typically undergoes afour stroke cycle: the cycle includes the intake stroke, compressionstroke, expansion stroke, and exhaust stroke. During the intake stroke,generally, the exhaust valve 54 closes and intake valve 52 opens. Air isintroduced into combustion chamber 30 via intake manifold 44, and piston36 moves to the bottom of the cylinder so as to increase the volumewithin combustion chamber 30. The position at which piston 36 is nearthe bottom of the cylinder and at the end of its stroke (e.g. whencombustion chamber 30 is at its largest volume) is typically referred toby those of skill in the art as bottom dead center (BDC). During thecompression stroke, intake valve 52 and exhaust valve 54 are closed.Piston 36 moves toward the cylinder head so as to compress the airwithin combustion chamber 30. The point at which piston 36 is at the endof its stroke and closest to the cylinder head (e.g. when combustionchamber 30 is at its smallest volume) is typically referred to by thoseof skill in the art as top dead center (TDC). In a process hereinafterreferred to as injection, fuel is introduced into the combustionchamber. In a process hereinafter referred to as ignition, the injectedfuel is ignited by known ignition means such as spark plug 92, resultingin combustion. However, in other examples compression ignition may beused. During the expansion stroke, the expanding gases push piston 36back to BDC. Crankshaft 40 converts piston movement into a rotationaltorque of the rotary shaft. Finally, during the exhaust stroke, theexhaust valve 54 opens to release the combusted air-fuel mixture toexhaust manifold 48 and the piston returns to TDC. Note that the aboveis shown merely as an example, and that intake and exhaust valve openingand/or closing timings may vary, such as to provide positive or negativevalve overlap, late intake valve closing, or various other examples.

A schematic depiction of a vehicle 200 including a first vehiclesubsystem 202 and a second vehicle subsystem 203 is shown in FIG. 2. Asillustrated an intake system 204 including intake manifold 44 is coupledto engine 10 which is coupled to exhaust system 206. The first subsystemis coupled to vacuum passage 84. Vacuum passage 84 is coupled to theintake manifold via vacuum port 80 including a flow disruptor 88.Additionally, the second subsystem is coupled to vacuum passage 86.Vacuum passage 86 is coupled to the intake manifold via vacuum port 82.

As previously discussed, the vehicle subsystems may be operated toenable gases to flow through the intake ports while a vacuum is presentin the intake manifold. In this way, fluidic communication between thefirst vehicle subsystem and the intake manifold may be selectivelyenabled. It will be appreciated that a vacuum may be generated whencombustion cycles are occurring in the engine and the throttle is atleast partially obstructing airflow in the intake system. For example,the evaporative emission system may be purged while a vacuum isgenerated in the intake manifold. Purging the evaporative emissionsystem may include enabling fluidic communication between a vaporcanister and the intake manifold. Additionally, air may be circulatedthrough the crankcase to the intake manifold when a vacuum is present inthe intake manifold. Moreover, exhaust gas may be re-circulated via theEGR system when a vacuum is present in the intake manifold. The EGRsystem may include a loop coupling the intake system to the exhaustsystem. Additionally, the brake system may enable fluidic communicationwith the intake manifold when additional braking assistance has beenrequested and a vacuum is present in the intake manifold.

Now referring to FIG. 3 showing a perspective view of an example intakemanifold 300 configured to supply air to an I-4 engine, which may be aturbocharged or naturally aspirated engine. It will be appreciated thatthe intake manifold shown in FIG. 3 is drawn approximately to scale.Intake manifold 300 may be intake manifold 44 shown in FIG. 1. Theintake manifold may include an upper shell 302 and a lower shell 304.The upper and lower shells may be molded via a suitable molding process,such as shell molding. However, in other embodiments the upper and lowershells may be constructed via another suitable technique. Additionally,the upper and lower shells are held together by fasteners (not shown)and sealed with gaskets to reduce the possibility of drawing unmeteredair into the engine.

Lower shell 304 includes a throttle body mounting flange 306 forcoupling a throttle body (not shown) to intake manifold 300. Thethrottle body effective area may be increased and decreased to allow theengine air amount to meet operator demands by opening and closing athrottle valve. In this way, a vacuum may be generated within the intakemanifold during certain operating conditions.

The intake manifold may further include a plurality of intake runners307 positioned downstream of the throttle body mounting flange. Eachintake runner may be coupled to at least one engine intake valve. Thus,the intake manifold may direct gases into the engine for combustion. Theintake runners are discussed in greater detail herein with regard toFIGS. 6-7.

The intake manifold further includes a throat 308 having a first vacuumport 310 and a second vacuum port 312 coupled thereto. It will beappreciated that the first and second vacuum ports are positioneddownstream of the throttle body (not shown) and upstream of intakerunners 307. As previously discussed, each of the vacuum ports may becoupled to one of the following subsystems: a crankcase ventilationsystem, a brake system, an evaporative emission system, and an EGRsystem via a vacuum passage. In other embodiments additional oralternate ports may be included in throat 308.

Flow disruptor 316 is disposed within an outlet of the first vacuum port310, but not in port 312. The flow disruptor may be integrally moldedinto the first vacuum port, in some examples. As depicted the flowdisruptor includes a cross-beam 318 traversing an outlet of the firstvacuum port. The geometric characteristics of the flow disruptor arediscussed in greater detail herein with regard to FIGS. 4 and 5.

The first vacuum port 310 may be positioned at an angle 319 with respectto the second vacuum port 312. Angle 319 may be between 45°-135°, suchas 90°. Additionally, the first vacuum port may be positioned at anangle 510, shown in FIG. 5, with respect to an axis of the throat of theintake manifold. Angle 510 may be between 45°-135°, such as 90°.Furthermore, the second vacuum port 312 may be positioned at an anglewith respect to an axis of the throat. Specifically the second vacuumport may be positioned at an angle between 45°-135°, such as 90°, withrespect to the axis of the throat of the intake manifold in someembodiments. It has been found that when the vacuum ports are positionedin this manner mixing within the intake manifold is promoted andflow-generated noises are reduced.

FIG. 4 shows a cross-sectional view of lower shell 304 of intakemanifold 300. Cutting plane 320, shown in FIG. 3, defines the crosssection shown in FIG. 4. Cross-beam 318 of the flow disruptor spans theoutlet of the first vacuum port. In particular, cross-beam 318 mayintersect the axis of the first vacuum port. However, it will beappreciated that in other embodiments the cross-beam may be offset fromthe axis of the first vacuum port. Additionally, outer-face 410 of thecross-beam is substantially planar. However, in other embodiments theouter-face may be curved. Further, in other embodiments, a plurality ofcross-beams may traverse the outlet of the first vacuum port.

As shown, the cross-beam may be substantially perpendicular to axis 412of throat 308. When the cross-beam is aligned in this way, a flowpattern within the intake manifold may be generated that reducesunwanted noises in the intake manifold. However other alignments mayalso be used, such as a range between 45°-135°. Furthermore, the ratiobetween the width of the outer-face of the cross-beam and the radius ofthe vacuum passage may be between 0.1 and 1. When the width to radiusratio is within the aforementioned range a flow pattern that reducesnoises within the intake manifold without reducing the flow-rate of thegas through the vacuum port by a significant amount may be generated.

FIG. 5 shows another cross-sectional view of the lower shell 304 ofintake manifold 300. Cutting plane 322, shown in FIG. 3, defines thecross section depicted in FIG. 5. Angle 510 defined by the intersectionof the axis of the throat and the axis of the first vacuum port may bebetween 45° and 135°, and in one example is about 90°, When angleswithin these ranges are formed, the mixing of gases from the two sourcesmay be increased. Specifically, it has been found that an angle of 90°for each of the angles is unexpectedly effective at reducingflow-generated noises within the intake manifold and promoting mixing ofthe gases. However, it will be appreciated that other angles may be usedin other embodiments.

As shown a cross-section of cross-beam 318 may define a wedge having aflat surface (i.e., outer-face 410) and two curved surfaces, 511 and512, forming an inner face 513. As shown the curved surfaces arecorrespondingly convex. However in other embodiments at least one of thecurved surfaces may be concave. The curved surfaces may decrease thewidth of the turbulent wake behind the flow disruptor. It will beappreciated that the curvature of the surfaces may be tuned to generatea desired amount of wake capable of reducing or in some caseseliminating flow-generated noises in the intake manifold. However inother embodiments the cross-section of the cross-beam may be circular.

Additionally, the first and second vacuum ports, 310 and 312, are offsetwith respect to the general direction of intake flow into throat 308. Inparticular the second vacuum port may be positioned downstream of thefirst vacuum port. When the vacuum ports are positioned in this way, theflow disruptor in the first vacuum port generates an increased amount ofturbulence downstream. Therefore, the flow disruptor may diminish thenoise generated by gas-flow over downstream vacuum ports. Therefore itmay be unnecessary to include flow disruptors in the second vacuum port.In other words, the second vacuum port 312 may have an unobstructedopening.

Arrow 514 denotes the general direction of gas flow into the intakemanifold from the first vacuum port. Arrow 516 denotes the generaldirection of gas flow into the intake manifold from the throttle body.Therefore it will be appreciated that gases may flow into the intakemanifold from a throttle body (not shown) through throat 308 and intointake runners 307.

FIG. 6 shows a cross-sectional view of the intake runners 307. Eachintake runner may include a partition 600 spanning a channel defined byan intake runner. Each partition may be substantially aligned with thegeneral direction of gas flow through the intake runners. In this way,the intake flow may be divided into multiple flows channels. Each of theintake runners may further include a runner outlet 700 shown in FIG. 7.Furthermore, each runner outlet may be fluidly coupled to at least oneengine intake valve.

FIG. 8 shows a front view of intake manifold 300. As shown, angle 800defines the spacing between the first and second vacuum ports withrespect to the general direction of intake air-flow through throat 308.In the depicted embodiment angle 800 is approximately 90°. However inother embodiments, angle 800 may be between 45°-120°. It will beappreciated that when the vacuum ports are positioned in this way theinteraction between the gases flowing out of the vacuum ports into theintake manifold with gases from the throttle body may be promoted.However, when angle 800 is increased the mixing of the exhaust gases maybe decreased.

FIG. 9 shows a side view of intake manifold 300. It will be appreciatedthat angle 900 defined between the axes of the intake runners and theaxis of the throat may be between 80°-110°. This type of alignmentincreases the compactness of the intake manifold. However, in otherembodiments other alignments are possible.

FIG. 10 shows a method 1000 for operation of an intake system includedin an internal combustion engine. Method 1000 may be implemented by thesystems, components, etc., described herein. However in otherembodiments the method may be implemented via other suitable systems andcomponents.

At 1002 the method includes selectively introducing gases into a vacuumport leading to an engine intake manifold. In some examples selectivelyintroducing gases into a vacuum port may include at 1004 actuating oneor more valves. It will be appreciated that the vacuum port may becoupled to a crankcase ventilation system, an evaporative emissionsystem, a brake system, and an EGR system. Therefore selectivelyintroducing gases into the vacuum port may include flowing gases from avapor canister to the vacuum port, flowing air from an engine crankcaseto the vacuum port, or flowing air from a brake system to assist thevehicle braking into the vacuum port. The gases may be introduced intothe vacuum port during selected operating conditions, as previouslydiscussed.

At 1006 the method includes splitting said gases around a flowdisrupting cross-beam in an outlet of the vacuum port to increase gasturbulence. As previously discussed the cross-beam may be positionedperpendicular to the axis of the intake manifold inlet. The cross-beammay be configured to increase the turbulence in the gases to reduceunwanted noises (e.g., resonance) within the intake manifold. Thecross-beam may also promote mixing of the gases from the vacuum portwith the gases from the throttle body, thereby decreasing combustionvariability.

At 1008 the method includes introducing the split gases into the intakemanifold. At 1010 the method may further include flowing the gases fromthe intake manifold into a plurality of intake runners. After 1010 themethod ends.

The systems and methods described above enable the reduction of unwantednoises within the intake manifold, thereby improving customersatisfaction. Additionally, the flow disruptor may also promote mixingof gases from a vacuum port with intake air, decreasing combustionvariability and improving combustion performance.

It will be appreciated that the configurations and/or approachesdescribed herein are exemplary in nature, and that these specificembodiments or examples are not to be considered in a limiting sense,because numerous variations are possible. The subject matter of thepresent disclosure includes all novel and nonobvious combinations andsubcombinations of the various features, functions, acts, and/orproperties disclosed herein, as well as any and all equivalents thereof.

The invention claimed is:
 1. A method for an intake system in an enginefor a vehicle, comprising: selectively introducing gases into a vacuumport leading to an engine intake manifold, including flowing air from abrake system to assist vehicle braking into the vacuum port; splittingsaid gases around a flow disrupting cross-beam in an outlet of thevacuum port to increase gas turbulence; and introducing the split gasesinto the intake manifold.
 2. The method according to claim 1, furthercomprising flowing gases into a plurality of intake runners from theoutlet.
 3. The method according to claim 1, where selectivelyintroducing gases into the vacuum port includes flowing gases from avapor canister to the vacuum port.
 4. The method according to claim 1,where selectively introducing gases into the vacuum port includesflowing air from an engine crankcase to the vacuum port.
 5. An intakesystem of an engine, comprising: an intake manifold having a pluralityof runners, each intake runner including a partition substantiallyaligned with a general direction of gas flow through the intake runners;a first vacuum port located in said intake manifold and in an air flowpath downstream of a throttle body and upstream of a plurality of intakerunners, the first vacuum port including a molded flow disruptorincluding a cross-beam traversing an outlet of the first vacuum port; afirst vacuum passage coupling the first vacuum port to a first vehiclesubsystem; and a second vacuum port having an unobstructed openingpositioned in said intake manifold downstream of the first vacuum port,the second vacuum port coupled to a second vehicle subsystem via asecond vacuum passage.
 6. The intake system of claim 5, wherein saidfirst vacuum port is at least one of a brake boost port, a positivecrankcase ventilation port, and a fuel vapor purge port.
 7. The intakesystem of claim 5, wherein said flow disruptor includes at least onecross-beam.
 8. The intake system of claim 5, wherein an axis of thefirst vacuum port intersects an axis of a throat of the intake manifold.9. The intake system of claim 5, wherein said flow disruptor isintegrally molded into the first vacuum port.
 10. The intake system ofclaim 5, wherein said cross-beam includes an outer face that issubstantially planar.
 11. The intake system of claim 5, wherein theratio between the width of the cross-beam and the radius of the firstvacuum passage is between 1 and 0.1.
 12. The intake system of claim 5,wherein the cross-beam is oriented at an angle between 45 and 135degrees with respect to an axis of a throat in the intake manifold.